API documentation — InboxVerify

Authentication

Create an API key in your dashboard under API Keys and send it as a bearer token. Keys are secrets — never put them in front-end code.

curl -X POST https://inboxverify.io/api/v1/domain/check \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"domain": "example.com"}'

Responses & errors

Every response has success, data and meta. Reports use the statuses pass, warning, fail, unknown and info. unknown means a check could not be completed and is never counted as a pass.

{
  "success": true,
  "data": {
    "id": "7c0f…", "service": "spf", "target": "example.com",
    "status": "completed", "overall": "warning", "score": 82,
    "report": { "headline": "…", "sections": [ { "title": "SPF record", "status": "pass", "checks": [ … ] } ], "data": { … } }
  },
  "meta": { "credits_used": 0, "credits_remaining": 1240 }
}

HTTP	code	Meaning
401	unauthenticated	Missing or invalid API key
402	insufficient_credits	Not enough credits
403	service_disabled	The tool is disabled
422	validation_failed / invalid_target	Bad input, or a private / internal target
429	rate_limited	Too many requests (see Retry-After)

Rate limits & credits

Each key has a per-minute limit (headers X-RateLimit-Limit / X-RateLimit-Remaining) and every tool has its own per-minute limit. Credits are deducted when a check starts and refunded automatically if it fails. Current costs:

Service	Credits
Email verification	1 per email
Problem Solver	3 (first 3/day free)
Inbox Checker	2 (first 5/day free)
Header Analyzer	free
Bounce Explainer	free
Domain Checker	2 (first 5/day free)
MX Checker	free
SPF Checker	free
DKIM Checker	free
DMARC Checker	free
PTR / Reverse DNS	free
SMTP Tester	1 (first 10/day free)
Blacklist Checker	1 (first 10/day free)
IP / Domain Reputation	2 (first 5/day free)

Async requests

Requests wait for the result by default. For slow checks (domain, SMTP, blacklist) you may add "async": true: you get 202 with an id, then poll GET /scans/{id} until status is completed or failed.

Endpoints

https://inboxverify.io/api/v1

POST/email/verify

Verify one email address.

{
    "email": "user@example.com"
}

POST/email/check

Full technical diagnosis of an email address.

{
    "email": "user@example.com",
    "mailbox": true
}

POST/domain/check

Domain Email Health Report.

{
    "domain": "example.com",
    "smtp": true
}

POST/mx/check

MX records, IPs, reverse DNS, optional SMTP.

{
    "domain": "example.com",
    "smtp": false
}

POST/spf/check

SPF validation, lookup count, include tree. Optional IP test.

{
    "domain": "example.com",
    "ip": "203.0.113.10"
}

POST/dkim/check

DKIM selector lookup or discovery.

{
    "domain": "example.com",
    "selector": "google"
}

POST/dmarc/check

DMARC policy, tags and reporting.

{
    "domain": "example.com"
}

POST/blacklist/check

IP or domain blocklist check.

{
    "target": "203.0.113.10"
}

POST/smtp/check

SMTP connection, EHLO, STARTTLS and certificate.

{
    "host": "mail.example.com",
    "ports": [
        25,
        587
    ]
}

POST/ptr/check

Reverse DNS and FCrDNS.

{
    "ip": "203.0.113.10",
    "hostname": "mail.example.com"
}

POST/header/analyze

Analyse raw email headers or a full message.

{
    "headers": "Received: from \u2026\nFrom: \u2026"
}

POST/bounce/explain

Explain a bounce / SMTP error.

{
    "message": "550 5.7.26 \u2026"
}

POST/reputation/check

Reputation indicators for an IP or domain.

{
    "target": "example.com"
}

POST/problem/solve

Prioritised fix plan for a problem (spam_folder, bouncing, not_receiving, blacklisted, new_domain, bulk_rules, spoofing).

{
    "problem": "spam_folder",
    "domain": "example.com"
}

GET/scans/{id}

Fetch a report by id (for async requests).

GET/scans

List your reports (paginated).

GET/account

Credits and available services with their cost.

Existing verification API

The original endpoints (GET /api/validate, POST /api/validate/bulk, POST /api/batch/upload, /api/jobs) keep working unchanged with the same keys. See the legacy documentation.

REST API